The federal government's proposed limits on methane emissions from oil and gas wells on public land will protect the atmosphere against one of the most potent greenhouse gases known to science.
Now the government needs to impose similar restrictions on wells on private land.
It's hard to overstate how crucial it is to keep methane from escaping -- quietly, invisibly -- into the air. Though methane accounts for just 10 percent of U.S. greenhouse-gas emissions, it's at least 25 times more effective than carbon dioxide at trapping heat. And unlike carbon dioxide, which has limited commercial value (so far, anyway), methane is a fuel, and a relatively clean-burning one, so letting it slip into the air both wastes money and hurts the climate.
The Interior Department's proposed rules, issued Friday, would require drillers to reduce the methane that leaks or is purposely vented or flared from wells on government land, cutting the emissions from these wells by half. This effect would be limited, however, because only 11 percent of the country's natural gas is extracted on public land, and only 5 percent of onshore oil production is on federal property.
To make bigger difference, tighter rules would need to be applied to oil and gas wells on private land. The EPA moved in that direction last year, when it proposed regulations for new or modified wells on private land.
However, existing wells, which often use out-of-date technology that allows greater methane leakage, are the bigger problem, and therefore in greater need of restrictions. The EPA should follow the Interior Department's lead.